Recently, with an increase in demands for a larger-sized display, the size of a glass substrate has exceeded 1 m×1 m and the size of an application (coating) apparatus has also increased correspondingly. A liquid material application device mainly used in the past is of the type that a liquid material is applied while a table on which a substrate is placed is moved in the XY-directions to change the relative positional relationship between a nozzle and a table. However, a gate type structure has been more popularly used for the reasons that an increase in weight of the table makes it more difficult to control the table and increases the influence of vibrations during the operation.
As one example of the gate-type liquid material application device, Patent Document 1 discloses a device in which a substrate holding mechanism for holding a substrate formed with a paste pattern is held movable only in one direction, two sets of head support mechanisms each provided with an application head for applying a paste onto the substrate, the application head being supported on the head support mechanism to be movable in a direction perpendicular to the moving direction of the substrate, one of the head support mechanisms is fixed to a mount base, and the other head support mechanism is movable in the moving direction of the substrate. It is also disclosed that the other head support mechanism is constructed to be not movable in the moving direction of the substrate while the paste pattern is being drawn on the substrate.
Further, Patent Document 2 discloses a paste application device for applying and drawing a paste pattern in a desired shape on a substrate placed on a table, wherein the paste application device comprises a frame which is movable in one direction within a plane parallel to a surface of the substrate placed on the table and which is extended in a direction differing from the one direction, a plurality of application heads each including a linear motor movable in the extending direction of the frame and having a paste storage tube and a paste discharge port through which the paste filled in the paste storage tube is discharged, and control means for executing control to move the frame relative to the table within a range in which the paste discharge port is positioned to face the substrate placed on the table, and to discharge the paste from the paste discharge ports of the plurality of application heads while moving the plurality of application heads relative to the frame, the plurality of application heads applying and drawing the paste pattern in the desired shape on the substrate.
Patent Document 1: Japanese Patent Laid-Open No. 2002-346452
Patent Document 2: Japanese Patent Laid-Open No. 2003-225606